Public ACLs are available for use by any user in the repository. Public ACLs created by the repository owner are called system ACLs. System ACLs can only be managed by the repository owner. Other public ACLs can be managed by their owners or a user with Sysadmin or Superuser
privileges.

Private ACLs are created and owned by a user other than the repository owner. However, unlike public ACLs, private ACLs are available for use only by their owners, and only their owners or a superuser can manage them.